Base and socket for radio tubes



Mmh 23,1937; D. D. IS'RAEL 2,074,397

t BASE AND SOCKET FOR RADIO TUBES Filed April 5, 19:54

-WI'II n W A Il l INV ENT OR. [70mm/VB fsk/:EL:

' VFILZZ. I i mwa/91%@ ATTORNEYS.

Patented Mar. 23, `1937 UNITED STATES .PATENT orrics The Crosley Radio Corporation, Cincinnati,

Ohio, a corporation of Ohio 5 Claims.

My invention has to do primarily with appropriate bases and sockets for very small radio tubes. Where, for considerations of space in the radio V set, very small tubes are designed, it is obvious 5 that the desired space economy will not be realized if these tubes have bases ofthe ordinary size, and are designed for the ordinary sockets. Consequently, a tube base and socket must be designed comparable in space economy with the l tubes. This matter has, however, presented some serious problems, since it is not possible merely to reduce the size of the present tube bases and sockets while retaining the usual construction. Moreover, it is not practicable, even in tube bases l and sockets of the ordinary type, to retain the same general construction and greatly increase the number of terminals. While I shall describe my novel tube base and socket particularly in connection with very tiny tubes,it will be under- 20 stood that my invention is not limited thereto, although of especial importance therein, and that its principles may be applied to tube sockets of the larger type, particularly where it is desired to increase the number of terminals. It may be 25 said parenthetically, however, that there appears to be a limit to the number of terminals which may be brought out through the base of a tube, this limit being the number which may be pressed into the squeezed portion of the glass at 30 the base of the tube.

So serious have these problems been in connection with the manufacture of small tubes, that it has hitherto been vproposed to do away with any socket, and in some instances, to do away with any 35 tube base, merely soldering the tube leads to the various leads of the radio set or other apparatus. This, however, does not give a very practical construction, for the reason that tubes may not easily be replaced therein, inasmuch as the re- 40 placement of tubes would ordinarily not only require a skilled worker, but also an electrician who understood the nature of the circuits Ain the set.

In designing a tube base and socket for the purpose referred to, it is necessary to design them 45 so that they will have a low capacity. Moreover,

it has been found in operation, that it is not practicable to bring out the tube leads through the sides of a tube base and solder them to sidewise disposed members. While itis, of course, possible 50 to, do this, it greatly hampers production, and it likewise prevents the employment of dip soldering operations. Since it is not practicable Where the space is very limited, to use the ordinary prong type tube bases, I have provided, in my invention,

55 for a construction of a tube base and socket hav- Application April 5. 1934, serial No. naiss (Cl. 1TB-$28) ing sidewise disposed contact members, but also having provision for bringing the tube leads out through the bottom of the tube base.

I shall describe my invention in connection with a tiny tube base, say of .812 extreme external diameter, and a depth of 19/32". The tube socket in which this base is to be used will have a maximum diameter 'of but 1". It will be understood, however, that these dimensions are not limitations upon my invention, but may be varied in either direction as desired. 4

The various objects of my invention which will be clear to one skilled in the art from the loregoing and following parts of my specifications, I accomplish by that certain construction and'arrangement of parts oi which I shall now describe the aforesaid exemplary embodiment. Reference is made to the drawing which is on a considerably enlarged scale, and in which- Figure 1 is an assembly drawing of a tube base and socket in interengaging relationship.

Figure 2 is a plan view of the socket.

Figure 3 is a bottom plan view of the tube base.

Figure 4 is a partial sectional lview of one of my tube bases having a somewhat diilerent type of construction.

Figure 5 is a partial sectional view of still another construction oi my tube base.

Essentially in the practice oi my invention, I provide a base of insulating material; and generally of cup-shaped formation. .This base may be of any suitable material including, but without limitation, any of those molded insulating materials in current use for like purposes. Sidewise disposed contact strips are arranged about the external surface of the cup. These strips turn over the bottom portion of the cup, andmeans are provided permitting the tube leads to be led out therethrough on the bottom of the cup and soldered or otherwise joined to the contact members. The socket likewise is preferably in the form at least of a hollow cylindrical member o insulating material, with' resilient contact strips disposed about the inner cylindrical surface thereof. Certain types of this construction will now be described in detail.

Referring iirst to Figures l and 3, I have shown at i a tube base of cup-shape formation, having a bottom 2. The tube 3 may be held therein in the usual way, as by means of an insulative cementing substance 4. I have shown in the sectional view of Figure 1, a pair of contact strips 5 lying along the outer surface of the cup I. .At their upper ends, in this form ot tube base, the strips are bent over as at 5a, and it is possible in this construction to mold the tube base I with these strips in position. Where this is done, the

turned over portions a will preferably be notched,

grooved, distorted, or otherwise treated to pro- 5 vide a secure anchorage inthe insulating material of the base I.

The strips 5 are likewise turned over so as to underlie the bottom of the cup as at 5b. They may be fastened to the bottom of the cup. by grommets 6, if desired, and -this is a most convenient way ofproviding a-means for bringing out the tube leads 1. These leads having been brought out' as described, may then be soldered to the grommets and/or turned over portions 5b l5 of the contact strips. In some constructions the use of grommets may not be necessary, particularly where the contact strips are molded into'the cup, corresponding holes being merely provided in the bottom 2 of the cup and in the turned over portions 5b of the contact members, and the tube leads being soldered directly to these contact members.

In Figure 3 I have shown a bottom plan view of a tube base such as that indicated in Figure 2 5 1, the base having eight contact members. It will be obvious that more or less may be used. Where eight or more are used, I prefer. to provide the bottom 2 of the cup with an upstanding spider formation 8,' having radiating upstanding arms 9` separating the portions 5b of the contact strips. Where fewer contact strips are employed,

this spider arrangement, the purpose of which is to prevent electrical leakage, is not necessary.

It will be clear that the cup I may be formed of bakelite or other insulating material, in a single molding operation, and, as indicated, that at least the upper ends of the contact strips 5 may be molded therein. The bodies of the con-` tact strips 5 preferably, although not necessarily, project beyond the surface of the cylindrical portion of the cup I. The cup may have an upper boss or enlarged annular portion Ia, if desired.

Other constructions are likewise practical. I have shown in Figure 4, the cup I,`bearing' in the boss Ia, vertically disposed orices I@ for the reception of straight sided contact strips II These strips are not molded in, but have their ends inserted into the orifices I6 after the formation of the cup I. Their ends are again bent over-as at IIa and preferably fastened by the grommets 6. Again, I have shown in Figure 5 a cup I, in which the contact members I2 are fastened at the bottom by a grommet I3 and'at the top by another grommet It. In this modification, the external surface of the cup I may be recessed as at I5, to accommodate the thickness of the head of the grommet It. The leads of the tube may, if preferred, be lbrought out through the grommets It.

It will be understood that the tube base which I have described, is not of necessity limited to the use of a socket. If it is preferred in any radio set or similar apparatus, the circuit leads of the set may be soldered or otherwise attached to tlie contact members 5, II or I2 of the tube base. However, it will ordinarily be preferred, for reasons given hereinabove, to use a radio tube having my tube base in a socket, and I have devised a socket adapted for use therewith which is =illustrated in section and in plan respectively `in Figures 1 and 2.l The socket comprises a cylindrical body I6, and also, if desired, a bottom II. I have shown the portion I 6 as having a cylindrical outer surface, and have not shown any means for the attachment f the socket to a suitable chassis.

'l Such means may be any desired, and it will be clear that perforated areas may be attached to the body I6, or the body I6 grooved to receive the edges of the metal chassis, or any other suitable provision made for attachment as may be 5 found necessary or desirable.- The interior cylindrical surface of my socket is provided with longitudinally extending grooves I8 terminating in perforationsIS through the bottom of the socket. Near the upper ends of these grooves, I provide offset but communicating grooves I9a.. These grooves lila are wider than the grooves I8, for a purpose hereinafter to be desczibed. The molded body of my socket need comprise only the construction thus far described, together with such attachment means as may be found desirable. It remains to provide my socket with suitable contact members. These are in the form of slightly bowed metal strips 2li of resilient material. These strips have an upper portion 2| terminating in extending ears 22, giving to my contact strip a somewhat T-shaped formation. The upper portion is offset from the body of the strip by a bend 23. The strip is inserted into the socket with its body extending in the groove I8, its head 2i lying in the groove I 9a, whereby the strip is held from downward displacement, and its tail extending through the perforation I 9 in the bottom of the socket. The tail 24 is then given a slight twist, as shown at 25, which prevents the upward dislodgment thereof. It has been said that the strips 20 are slightly bowed. The purpose of this is to cause them to make resilient contact with the contact strips 5 of the tube base. When my socket is in use, the leads of the radio set or other apparatus are soldered or otherwise suitably fas- A tened to the tails 2l.

'It is practicable so to construct the socket .that the grooves I8 are deeper than the width of the contact strips 20, and so that the contact strips 5, I I or I2 must likewise enter these grooves. This construction prevents a rotary displacement of the tube base in the socket. In order to secure the proper orientation of the -tube base in the socket, it is my practice to make one of the contact strips 5, II or I2 on the tube base wider than the others, as shown at 5c in Figure 3. Similarly, Imake one of my contact strips 20a in the socket wider than the other, and dispose it in a wider groove I8a in the socket. Consequently, it is not possible to insert my base in my socket in the wrong way. However, I am not limited to this construction. With the contact strips on the tube base all of the same width, it is possible, for example, to mold a ridge in the tube base. which can be inserted in a corresponding depression in the socket lying between adjacent grooves I8. Other methods of orientation may likewise be adopted. K

It will be clear that modifications may be made in my invention without departing from the spirit thereof.

Having thus describedv my invention, what I claim as new and desire to secure by Letters Patent, isz- 1. A tube socket comprising a casing of insulaing material having a central cylindrical `orice, said casing having longitudinally disposed grooves in the interior surface of said orifice, displaced interconnecting wider grooves near the top thereof, and T-shaped contact strips longitudinally disposed in said orifice, the heads of said contact strips entering said wider displaced grooves, for the purpose described.

2. A tube socket comprising a casing oi insu- 75 lating material having a central cylindrical oriiice, said casing having longitudinally disposed grooves in the interior surface of said orlilce, displaced interconnecting wider grooves near the 5 top thereof, and T-shaped contact strips 1ongi tudinally disposed in said orice,the heads of said contact strips entering said wider displaced grooves, for the purpose described, the ends of said contact strips being bent beyond said casing l0 soy as to prevent displacement thereof.

3. A tube socket comprising a casing of insulating material having a central cylindrical orice, said casing having longitudinally disposed grooves in the interior surface of said orifice.

15 displaced interconnecting wider grooves near the top thereof, and T-shaped contact strips longitudinally disposed in said oriilce, the heads of said contact strips entering said wider displaced grooves, for the purpose described, said longil20 tudinally disposed grooves being deeper than the width of said contact strips so as to accept a portion at least of cooperating contact strips on a tube base.

4. A` tube socket comprising a casing of insulating material having a central cylindrical orivilce, said casing having longitudinally disposed grooves in the interior surface of said orlnce, displaced interconnecting wider grooves near the top thereof, and Tshaped contact strips longitudinally disposed in said oriilce, the heads of' said contact -strips entering said wider displaced p grooves, for the purpose described, and means for insuring the proper orientation of a tube base in said socket.

5. A tube socket comprising a casing of insulating material having a. central cylindrical oriilce. said casing having longitudinally disposed grooves in the interior surface of said oriiice, displaced interconnecting wider grooves near the top thereof, and T-shaped contact strips longitudinaily disposed in 'said orifice. the heads of said contact strips entering said wider displaced grooves, for the purpose described, and means for insuring the proper orientation of a tube base in said socket, said means comprising a provision of one groove which is wider than the remainder thereof.

DORMAN D. ISRAEL. 

